Group DM limit bypass via concurrent additions
Published Mar 26, 2025 · Updated Mar 26, 2025
Race condition in Discourse stable before 3.3.4 and beta before 3.4.0.beta5 allows remote authenticated users to exceed group DM limits. The add_users_to_channel service checks capacity and adds members without serializing concurrent requests, so parallel additions can pass the same limit check. The user must already be able to add members and bring the group DM close to its limit; exploitation alters membership beyond the configured cap.
Summary
What happened
Race condition in Discourse stable before 3.3.4 and beta before 3.4.0.beta5 allows remote authenticated users to exceed group DM limits. The add_users_to_channel service checks capacity and adds members without serializing concurrent requests, so parallel additions can pass the same limit check. The user must already be able to add members and bring the group DM close to its limit; exploitation alters membership beyond the configured cap.
The record
- CVE
- CVE-2025-24808
- Published
- Mar 26, 2025
- Updated
- Mar 26, 2025
- Vendor
- Discourse
- Product
- Discourse
- Classifications
- CWE-362, CAPEC-26
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 26, 2025CVE publishedPublication date reported by the CVE source.
- Mar 26, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.3.4
- Affected versionversion=>= 3.4.0.beta1, < 3.4.0.beta5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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